/*
 * Copyright (c) 2002-2020 Manorrock.com. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright notice, 
 *      this list of conditions and the following disclaimer.
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *   3. Neither the name of the copyright holder nor the names of its 
 *      contributors may be used to endorse or promote products derived from
 *      this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package jakarta.servlet.http;

import java.io.IOException;
import jakarta.servlet.FilterChain;
import jakarta.servlet.GenericFilter;
import jakarta.servlet.ServletException;
import jakarta.servlet.ServletRequest;
import jakarta.servlet.ServletResponse;

/**
 * A HTTP filter.
 *
 * @author Manfred Riem (mriem@manorrock.com)
 */
public abstract class HttpFilter extends GenericFilter {

    /**
     * Process the filter.
     * 
     * @param request the request.
     * @param response the response
     * @param chain the filter chain
     * @throws IOException when an I/O error occurs.
     * @throws ServletException when a servlet error occurs.
     */
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        if (request instanceof HttpServletRequest && response instanceof HttpServletResponse) {
            HttpServletRequest httpServletRequest = (HttpServletRequest) request;
            HttpServletResponse httpServletResponse = (HttpServletResponse) response;
            this.doFilter(httpServletRequest, httpServletResponse, chain);
        } else {
            throw new ServletException("not a HTTP request or a HTTP response");
        }

    }

    /**
     * Process the filter.
     *
     * @param request the request.
     * @param response the response.
     * @param chain the chain.
     * @throws IOException when an I/O error occurs.
     * @throws ServletException when a servlet error occurs.
     */
    protected void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        chain.doFilter(request, response);
    }
}
